In nuclear medicine, scintillation crystals have become important components of medical imaging devices. The performance of these medical imaging devices, including Positron Emission Tomography (PET) scanners, largely depends on the quality and uniformity of scintillation crystals and on related crystal block array assemblies. The cost of making such medical imaging devices is generally expensive. Thus, there is a need to reduce manufacturing costs by simplifying the procedures for making scintillation crystal block arrays.
In a general sense, positron emission tomography is a medical imaging technique in which a patient ingests a radioactively tagged compound that mimics a naturally occurring compound. For reasons relating to the body's metabolism, the compound tends to accumulate in tumors. The radioactively tagged compounds tend to emit gamma rays. The gamma rays can be detected outside of the patient's body. In particular, when the scintillation crystals are struck by a gamma ray, they are likely to emit a photon (“scintillation”). The photon is in turn recognized by a photodetector, which generates an electronic signal. Various hardware and software components use the electronic signal to reconstruct the likely position (within a known tolerance) of the original gamma ray emission.
In accordance with known methods of making a crystal block array, a scintillation crystal boule may be cut and polished to generate a plurality of individual scintillation crystal pixels that are then each surrounded by Teflon tape and grouped into a crystal block array. In accordance with other known methods, a reflective sheet material matrix may be defined, and individual scintillation crystal pixels can be disposed within slots defined by the sheet material matrix. However, these methods produce crystal block arrays that include gaps and inconsistently packed pixels.
Better crystals and more uniform crystal block arrays provide better information about the gamma rays and thus provide a better image, and help lead to a better diagnosis, and potentially better medical treatment. Accordingly, and although some progress has made with respect to the development of crystal block arrays, there is still a need in the art for new crystal block arrays and related methods of manufacture to overcome the deficiencies and obstacles discussed above.